/* Copyright 2018 Paul Stoffregen
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this
 * software and associated documentation files (the "Software"), to deal in the Software
 * without restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef ethernet_h_
#define ethernet_h_

// All symbols exposed to Arduino sketches are contained in this header file
//
// Older versions had much of this stuff in EthernetClient.h, EthernetServer.h,
// and socket.h.  Including headers in different order could cause trouble, so
// these "friend" classes are now defined in the same header file.  socket.h
// was removed to avoid possible conflict with the C library header files.


// Configure the maximum number of sockets to support.  W5100 chips can have
// up to 4 sockets.  W5200 & W5500 can have up to 8 sockets.  Several bytes
// of RAM are used for each socket.  Reducing the maximum can save RAM, but
// you are limited to fewer simultaneous connections.
#if defined(RAMEND) && defined(RAMSTART) && ((RAMEND - RAMSTART) <= 2048)
#define MAX_SOCK_NUM 4
#else
#define MAX_SOCK_NUM 8
#endif

// By default, each socket uses 2K buffers inside the Wiznet chip.  If
// MAX_SOCK_NUM is set to fewer than the chip's maximum, uncommenting
// this will use larger buffers within the Wiznet chip.  Large buffers
// can really help with UDP protocols like Artnet.  In theory larger
// buffers should allow faster TCP over high-latency links, but this
// does not always seem to work in practice (maybe Wiznet bugs?)
//#define ETHERNET_LARGE_BUFFERS


#include <Arduino.h>
#include "Client.h"
#include "Server.h"
#include "Udp.h"

enum EthernetLinkStatus {
  Unknown,
  LinkON,
  LinkOFF
};

enum EthernetHardwareStatus {
  EthernetNoHardware,
  EthernetW5100,
  EthernetW5200,
  EthernetW5500
};

class EthernetUDP;
class EthernetClient;
class EthernetServer;
class DhcpClass;

class EthernetClass {
private:
  static IPAddress _dnsServerAddress;
  static DhcpClass* _dhcp;
public:
  // Initialise the Ethernet shield to use the provided MAC address and
  // gain the rest of the configuration through DHCP.
  // Returns 0 if the DHCP configuration failed, and 1 if it succeeded
  static int begin(uint8_t *mac, unsigned long timeout = 60000, unsigned long responseTimeout = 4000);
  static int maintain();
  static EthernetLinkStatus linkStatus();
  static EthernetHardwareStatus hardwareStatus();

  // Manual configuration
  static void begin(uint8_t *mac, IPAddress ip);
  static void begin(uint8_t *mac, IPAddress ip, IPAddress dns);
  static void begin(uint8_t *mac, IPAddress ip, IPAddress dns, IPAddress gateway);
  static void begin(uint8_t *mac, IPAddress ip, IPAddress dns, IPAddress gateway, IPAddress subnet);
  static void init(uint8_t sspin = 10);

  static void MACAddress(uint8_t *mac_address);
  static IPAddress localIP();
  static IPAddress subnetMask();
  static IPAddress gatewayIP();
  static IPAddress dnsServerIP() { return _dnsServerAddress; }

  void setMACAddress(const uint8_t *mac_address);
  void setLocalIP(const IPAddress local_ip);
  void setSubnetMask(const IPAddress subnet);
  void setGatewayIP(const IPAddress gateway);
  void setDnsServerIP(const IPAddress dns_server) { _dnsServerAddress = dns_server; }
  void setRetransmissionTimeout(uint16_t milliseconds);
  void setRetransmissionCount(uint8_t num);

  friend class EthernetClient;
  friend class EthernetServer;
  friend class EthernetUDP;
private:
  // Opens a socket(TCP or UDP or IP_RAW mode)
  static uint8_t socketBegin(uint8_t protocol, uint16_t port);
  static uint8_t socketBeginMulticast(uint8_t protocol, IPAddress ip,uint16_t port);
  static uint8_t socketStatus(uint8_t s);
  // Close socket
  static void socketClose(uint8_t s);
  // Establish TCP connection (Active connection)
  static void socketConnect(uint8_t s, uint8_t * addr, uint16_t port);
  // disconnect the connection
  static void socketDisconnect(uint8_t s);
  // Establish TCP connection (Passive connection)
  static uint8_t socketListen(uint8_t s);
  // Send data (TCP)
  static uint16_t socketSend(uint8_t s, const uint8_t * buf, uint16_t len);
  static uint16_t socketSendAvailable(uint8_t s);
  // Receive data (TCP)
  static int socketRecv(uint8_t s, uint8_t * buf, int16_t len);
  static uint16_t socketRecvAvailable(uint8_t s);
  static uint8_t socketPeek(uint8_t s);
  // sets up a UDP datagram, the data for which will be provided by one
  // or more calls to bufferData and then finally sent with sendUDP.
  // return true if the datagram was successfully set up, or false if there was an error
  static bool socketStartUDP(uint8_t s, uint8_t* addr, uint16_t port);
  // copy up to len bytes of data from buf into a UDP datagram to be
  // sent later by sendUDP.  Allows datagrams to be built up from a series of bufferData calls.
  // return Number of bytes successfully buffered
  static uint16_t socketBufferData(uint8_t s, uint16_t offset, const uint8_t* buf, uint16_t len);
  // Send a UDP datagram built up from a sequence of startUDP followed by one or more
  // calls to bufferData.
  // return true if the datagram was successfully sent, or false if there was an error
  static bool socketSendUDP(uint8_t s);
  // Initialize the "random" source port number
  static void socketPortRand(uint16_t n);
};

extern EthernetClass Ethernet;


#define UDP_TX_PACKET_MAX_SIZE 24

class EthernetUDP : public UDP {
private:
  uint16_t _port; // local port to listen on
  IPAddress _remoteIP; // remote IP address for the incoming packet whilst it's being processed
  uint16_t _remotePort; // remote port for the incoming packet whilst it's being processed
  uint16_t _offset; // offset into the packet being sent

protected:
  uint8_t sockindex;
  uint16_t _remaining; // remaining bytes of incoming packet yet to be processed

public:
  EthernetUDP() : sockindex(MAX_SOCK_NUM) {}  // Constructor
  virtual uint8_t begin(uint16_t);      // initialize, start listening on specified port. Returns 1 if successful, 0 if there are no sockets available to use
  virtual uint8_t beginMulticast(IPAddress, uint16_t);  // initialize, start listening on specified port. Returns 1 if successful, 0 if there are no sockets available to use
  virtual void stop();  // Finish with the UDP socket

  // Sending UDP packets

  // Start building up a packet to send to the remote host specific in ip and port
  // Returns 1 if successful, 0 if there was a problem with the supplied IP address or port
  virtual int beginPacket(IPAddress ip, uint16_t port);
  // Start building up a packet to send to the remote host specific in host and port
  // Returns 1 if successful, 0 if there was a problem resolving the hostname or port
  virtual int beginPacket(const char *host, uint16_t port);
  // Finish off this packet and send it
  // Returns 1 if the packet was sent successfully, 0 if there was an error
  virtual int endPacket();
  // Write a single byte into the packet
  virtual size_t write(uint8_t);
  // Write size bytes from buffer into the packet
  virtual size_t write(const uint8_t *buffer, size_t size);

  using Print::write;

  // Start processing the next available incoming packet
  // Returns the size of the packet in bytes, or 0 if no packets are available
  virtual int parsePacket();
  // Number of bytes remaining in the current packet
  virtual int available();
  // Read a single byte from the current packet
  virtual int read();
  // Read up to len bytes from the current packet and place them into buffer
  // Returns the number of bytes read, or 0 if none are available
  virtual int read(unsigned char* buffer, size_t len);
  // Read up to len characters from the current packet and place them into buffer
  // Returns the number of characters read, or 0 if none are available
  virtual int read(char* buffer, size_t len) { return read((unsigned char*)buffer, len); };
  // Return the next byte from the current packet without moving on to the next byte
  virtual int peek();
  virtual void flush(); // Finish reading the current packet

  // Return the IP address of the host who sent the current incoming packet
  virtual IPAddress remoteIP() { return _remoteIP; };
  // Return the port of the host who sent the current incoming packet
  virtual uint16_t remotePort() { return _remotePort; };
  virtual uint16_t localPort() { return _port; }
};




class EthernetClient : public Client {
public:
  EthernetClient() : sockindex(MAX_SOCK_NUM), _timeout(1000) { }
  EthernetClient(uint8_t s) : sockindex(s), _timeout(1000) { }

  uint8_t status();
  virtual int connect(IPAddress ip, uint16_t port);
  virtual int connect(const char *host, uint16_t port);
  virtual int availableForWrite(void);
  virtual size_t write(uint8_t);
  virtual size_t write(const uint8_t *buf, size_t size);
  virtual int available();
  virtual int read();
  virtual int read(uint8_t *buf, size_t size);
  virtual int peek();
  virtual void flush();
  virtual void stop();
  virtual uint8_t connected();
  virtual operator bool() { return sockindex < MAX_SOCK_NUM; }
  virtual bool operator==(const bool value) { return bool() == value; }
  virtual bool operator!=(const bool value) { return bool() != value; }
  virtual bool operator==(const EthernetClient&);
  virtual bool operator!=(const EthernetClient& rhs) { return !this->operator==(rhs); }
  uint8_t getSocketNumber() const { return sockindex; }
  virtual uint16_t localPort();
  virtual IPAddress remoteIP();
  virtual uint16_t remotePort();
  virtual void setConnectionTimeout(uint16_t timeout) { _timeout = timeout; }

  friend class EthernetServer;

  using Print::write;

private:
  uint8_t sockindex; // MAX_SOCK_NUM means client not in use
  uint16_t _timeout;
};


class EthernetServer : public Server {
private:
  uint16_t _port;
public:
  EthernetServer(uint16_t port) : _port(port) { }
  EthernetClient available();
  EthernetClient accept();
  virtual void begin();
  virtual size_t write(uint8_t);
  virtual size_t write(const uint8_t *buf, size_t size);
  virtual operator bool();
  using Print::write;
  //void statusreport();

  // TODO: make private when socket allocation moves to EthernetClass
  static uint16_t server_port[MAX_SOCK_NUM];
};


class DhcpClass {
private:
  uint32_t _dhcpInitialTransactionId;
  uint32_t _dhcpTransactionId;
  uint8_t  _dhcpMacAddr[6];
#ifdef __arm__
  uint8_t  _dhcpLocalIp[4] __attribute__((aligned(4)));
  uint8_t  _dhcpSubnetMask[4] __attribute__((aligned(4)));
  uint8_t  _dhcpGatewayIp[4] __attribute__((aligned(4)));
  uint8_t  _dhcpDhcpServerIp[4] __attribute__((aligned(4)));
  uint8_t  _dhcpDnsServerIp[4] __attribute__((aligned(4)));
#else
  uint8_t  _dhcpLocalIp[4];
  uint8_t  _dhcpSubnetMask[4];
  uint8_t  _dhcpGatewayIp[4];
  uint8_t  _dhcpDhcpServerIp[4];
  uint8_t  _dhcpDnsServerIp[4];
#endif
  uint32_t _dhcpLeaseTime;
  uint32_t _dhcpT1, _dhcpT2;
  uint32_t _renewInSec;
  uint32_t _rebindInSec;
  unsigned long _timeout;
  unsigned long _responseTimeout;
  unsigned long _lastCheckLeaseMillis;
  uint8_t _dhcp_state;
  EthernetUDP _dhcpUdpSocket;

  int request_DHCP_lease();
  void reset_DHCP_lease();
  void presend_DHCP();
  void send_DHCP_MESSAGE(uint8_t, uint16_t);
  void printByte(char *, uint8_t);

  uint8_t parseDHCPResponse(unsigned long responseTimeout, uint32_t& transactionId);
public:
  IPAddress getLocalIp();
  IPAddress getSubnetMask();
  IPAddress getGatewayIp();
  IPAddress getDhcpServerIp();
  IPAddress getDnsServerIp();

  int beginWithDHCP(uint8_t *, unsigned long timeout = 60000, unsigned long responseTimeout = 4000);
  int checkLease();
};





#endif
